DANIELS
ELECTRONICS LTD.
TM
2-6
IM10-VR3H040-AB VHF Enhanced Extra Wideband Receiver Instruction Manual
2.4
21.4 MHz IF/Audio Main Board
The 21.4 MHz IF / Audio Main Board is the main board for all receivers up to 512 MHz. This
board provides interconnects for Daniels Synthesized and Crystal Controlled Oscillators, and
Daniels high performance and low current Front Ends. An F48 type connector plugs into
Daniels M3 Motherboard. The 21.4 MHz IF / Audio Main Board is configurable at the factory
for either narrow band or wide band channels. Different bands within a frequency range do not
require a configuration change.
2.5
Enhanced Front End
The FE3H040 Enhanced Front End is a highly integrated, frequency selective, down converter
used in Daniels Electronics standard MT-3 Low Band VHF FM receiver product line. The
FE3H040 Front End connects to the 21.4 MHz IF / Audio Main Board and the enhanced
Synthesizer to form a complete receiver.
The Enhanced Front End amplifies and down converts the RF signal to the IF frequency of
21.4 MHz. The FE3H035 and FE3H045 Front Ends use high side injection. The Enhanced
Front End consists of the following:
• Five Section L-C coupled Bandpass Filter
• Single Stage Low Noise RF Amplifier
• Image Rejection Filter
• Local Oscillator Low Pass Filter
• Double Balanced Active Mixer